Overview
| Stage | Permitting |
| Mine Type | Open Pit |
| Commodities |
|
| Mining Method |
|
As a result of an acquisition, AngloGold Ashanti now controls a past-producing mine site in southern Nevada known as the Sterling mine, which has one applicable mining lease that expires in 2029, with the option to extend the lease for an additional ten-year period. Although the Sterling mine is currently in care and maintenance status, it remains subject to complex permitting and regulatory requirements, including compliance with relevant provisions of the U.S. Federal Mine Safety and Health Act of 1977 and oversight by the U.S. Department of Labor’s Mine Safety and Health Administration (“MSHA”).
The Sterling project includes the Crown Block deposits of SNA, Secret Pass and Daisy, and the tenements surrounding the properties. |
Source:
p. 128
The Sterling project is an indirect wholly owned and managed by AngloGold Ashanti.
Contractors
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Deposit Type
- Sediment-hosted
- Carlin-type
- Breccia pipe / Stockwork
Summary:
Geology
The Sterling deposits are characterised as either epithermal deposits (Secret Pass) like the North Bullfrog and Silicon deposits or sediment-hosted deposits (Daisy, Sterling, and SNA). Oxidised gold appears to be controlled by thrust domains and steep north-striking faults in these deposits.
Deposit type
From oldest to youngest, stratified rock units on the Sterling property range from the Upper Proterozoic to the Ordovician part of the stratigraphic section. The host rocks of the 144 Zone mineralisation span the bottom of the Bonanza King Formation and the top of the Carrara Formation. Miocene quartz latite dykes of the SWNVF occur throughout the Sterling property, but most are along or close to the Reudy Fault zone. They normally range in thickness from 1.5m to about 9m, though some are considerably thicker. Most trend north-south and were probably intruded along faults or fractures. Clay-alteration of the dyke ranges from weak to locally intense. The dykes slightly pre-date the most important hydrothermal activity and gold mineralisation at Sterling.
The Daisy deposits are located in the footwall of the Fluorspar Canyon fault where it intersects a prominent north-south fault system that connects with the Reward deposit to the south. Daisy is a sediment-hosted gold deposit.
SNA can be described as a Carlin-type deposit hosted within Devonian carbonates in the footwall of the Fluorspar Canyon fault.
Mineralisation style
Sterling is typical of sediment-hosted, dis ........
Summary:
The Sterling mine, which is currently in care and maintenance, has a valid mining permit with a permitted heap leach pad expansion area. The reclamation and closure liabilities of the key exploration and mining properties are defined by state and federal regulations, and the operation is currently bonded in accordance with those requirements.
Open pit mining of the Sterling mine deposit began in 1980 and continued until 1989. Underground mining began in 1980 and proceeded until mid-1997 when market conditions impacted profitability. The Crown deposits contain mineralisation at or near the surface that is suitable for open pit mining methods.
Source:
Summary:
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Projected Production:
All production numbers are expressed as metal in doré.
Operational Metrics:
| Metrics | 2014 |
|
Tonnes processed
| 45,217 tons |
Reserves at December 31, 2022:
The Mineral Resource was constrained by pit optimisation at a gold price of $1,700/oz. The open pit Mineral Resource estimates are reported in situ and are contained within a confining open pit shell. Ordinary kriging techniques were used in the estimation model. Key parameters used: a gold cut-off grade of 0.24g/t, gold recoveries of 75 to 80%, mining costs of $2.16/t, process costs of $2.70/t, general and administrative costs of $1.00/t, and variable pit slope angles of 39° to 52° over the LOM.
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Inferred
|
33.41 Mt
|
Gold
|
0.85 g/t
|
0.91 M oz
|
Financials:
| | Units | 2016 |
|
Capital expenditures
|
M CAD
|
0.3
|
|
Revenue
|
M CAD
|
0.8
|
|
After-tax Income
|
M CAD
|
-8.9
|
Corporate Filings & Presentations:
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